Help with my truck

[c0ncEpT]

You say your vibration is RPM based not speed based correct?

[JoeliusZ28]

yep

[c0ncEpT]

Did you have to remove any pulleys? I would check them to make sure they are all on all the way if so.

[JoeliusZ28]

yes i did... and they all look good but ill check again

[Will]

I had a lot of trouble with the tensioner (sp?) pulley on my roommates truck, it got stuck and wouldn't spin right . . . check that?

edit: ooh, check the alternator too. I know it sounds crazy but my roommate's truck had a bad alternator and it caused it to have some of the same symptoms you're having.

[JoeliusZ28]

I had a lot of trouble with the tensioner (sp?) pulley on my roommates truck, it got stuck and wouldn't spin right . . . check that?

edit: ooh, check the alternator too. I know it sounds crazy but my roommate's truck had a bad alternator and it caused it to have some of the same symptoms you're having.

i lubricated the tensioner really good before reinstalling it, and the alternator is only 2 years old exactly.

ill give it all a once-over when i go up to autozone.

[Will]

My roommate's broken alternator was only 6 months old. Delco. I didn't think it could be broken either, but it was.

[JoeliusZ28]

"H02S 22 heater Condition (heated oxygen sensor bank 2 sensor 2)"

I wonder if it was burning coolant

[kammi10]

umm that could be...

[my95z28]

bank 2 sensor 2 would be post cat correct? why wouldn't it throw the initial o2? I thought that all the post o2 did was measuring if the cat was functioning correctly or not?

[nascarnate326]

soooo what does that mean joel?

[Will]

bank 2 sensor 2 would be post cat correct? why wouldn't it throw the initial o2? I thought that all the post o2 did was measuring if the cat was functioning correctly or not?

If the sensor is effed, maybe the cat is clogged?

[JoeliusZ28]

I dont think the cats are clogged but Im going to check them. Ive experienced a few of those now, and i dont think that is an issue here.

I have a vibration from something that is out of balance AND rpm related. So far, i still have no idea what it could be. It is only noticeable north of 3500 RPM or so, and isnt bad until 4500. I checked the pulleys when i put it back together but im going to check them again.

Would a gatorback accessory belt cause it? I did replace the accessory belt which was a non-gatorback.

An oxygen sensor could explain my weak throttle response and cruising power, but not the high RPM issue. The engine is clearly making power at WOT.

I'm going to replace the oxygen sensor when i go home next but that is not causing the vibration. Ive driven my Z28 without oxygen sensors and had no problems.

[93formulalt1]

My Blazer had the same symptoms, we went through hell to find out what it was when my Dad was still driving it. After he gave it to me, I checked it out, and the first thing I noticed was that the MAF Sensor was covered in all kinds of crud. I cleaned off the sensor wires with a clean cloth, put it all back together, and the problem was gone. . . I would definitely check the MAF, when it's dirty or going bad, it can cause the symptoms you are having. . .

[JoeliusZ28]

will do then, cant hurt